The effect of different nutritional systems on yield and yield components of sesame (Sesamum indicum L.) in competition and non- competition with weeds

Sustainable agriculture, with respecting ecological principles, can increase the efficiency of resources use and provide a longer-term benefit to humans, while providing a balance in the environment. The application of organic fertilizers with a view of replacing or significantly reducing the use of chemical fertilizers increases the quality and quantity of plants yield. Sesame is one of the most important oily and pharmaceutic seeds in agricultural areas, which is due to its high oil and protein content and antioxidant content in food, food supplements, medicine and industry. Therefore, this study was conducted to evaluate the various organic and biological nutrient systems on yield and yield components of sesame under competition and non-competition with weeds.

This experiment was conducted as a split plot in a randomized complete block design in three replications in Sari Agricultural Sciences and Natural Resources University in 2015. The treatments consisted of: competition between plants and weeds (weedy and weed free) as a main factor, and sub factor was fertilizer sources include sheep manure, pigeon manure, vermicompost fertilizer, bio-fertilizer (Nytrukara), sheep manure + biofertilizers, pigeon manure + biofertilizers, vermicompost + biofertilizer, urea fertilizer and control (no fertilizer). Dominant weeds were identified in the field as velvetleaf (Abutilon theophrassti L.), barnyardgrass (Echinochloa crusgalli L.), bermuda grass (Cynodon dactylon) and wild melon (Cucumis melo var. Agrestis).The studied traits included yield and yield components of sesame, weed density and weed biomass and competitive indices.

The results showed that the highest yield per unit area (2992 kg ha-1) was observed in the integrated treatment of sheep manure and Nytrvkara and the maximum harvest index (44 percent) was in integrated treatment of vermicompost and Nytrvkara in weed free condition, while, the lowest ones was at control in weed infestation. Also, nitrogen sources showed significant differences in weed density and biomass compared to control. In examining the ability to withstand competition (AWC), the results showed that the ability to compete with weeds tolerant, pigeon manure treatment had the highest ability to compete with weeds, while, after a pigeon manure, integrated managements enhance performance, as well as increased competitiveness.

Finally, based on the results of this study, it can be concluded that the combined use of fertilizers, with increasing sesame growth and no environmental side effect, reduces dry weight of weeds, reduces weed damage and also reduces the use of herbicides. So, it is a suitable method for the healthy and sustainable production of these products.